Application Ser. No. 12/553,971, filed Sep. 3, 2009 (hereinafter “the '971 application”), discloses a method and device for manipulating an object with a remote vehicle having an end effector attached to a manipulator arm. The end effector comprises a jamming material in a housing. The jamming material in the '971 patent is also referred to as a phase-change material, and “jamming,” as used herein, includes such phase change materials. The method comprises pressing the end effector housing to the object, activating the jamming material to grasp the object, and moving the manipulator arm to manipulate the object.
In accordance with various embodiments, the end effector includes a substantially air-impermeable housing that is filled with a jamming material. The composition of the housing can vary depending on the desired manipulation traits, the material contained in the housing, the size of the housing, and economic considerations. The material comprising the housing(s) should be at least minimally elastic or flexible and can have some degree of friction on its surface to aid in object manipulation. The housing(s) should also have a strength (e.g., tear resistance) that is sufficient for objects it is intended to manipulate. For example, a more tear resistant material is desirable when objects to be manipulated may have sharp edges or points, whereas tear resistance can be less critical when objects to be manipulated are smooth.
The housing may include, for example, a balloon such as a latex balloon, a platinum-cure or tin-cure silicone-based rubber, a plastic bag such as a zip lock bag, or a Kevlar composite. Kevlar can provide strength against puncturing and can be combined with a more elastic material to attain a desired flexibility for the housing. Platinum-cure or tin-cure RTV (room temperature vulcanizing) silicone-based rubbers can be desirable because they are easily molded into custom shapes. The housing can surround the jamming material and an activation device can be in communication with the jamming material. The activation device can be located inside or outside of a housing.
When end effector housings such as those disclosed in the '971 application are pressed against an object, the housings may be unable to surround the object to the extent necessary to securely grasp the object. Thus, existing housings may not be able to properly grasp an object to sustain or generate the pressure required to grasp the object for manipulation.